Balloon sounding of the atmosphere is part of ozone study being undertaken in SUPARCO to determine the vertical profile of ozone up to 30-35 km. The measurement plays an important
role in understanding the concentration of the ozone in the lower troposphere and how the ozone in the stratosphere and troposphere vary seasonally. These data are very valuable in conducting
numerous scientific studies. In conjunction with global/regional data received from satellites, valuable conclusions can be drawn. For example, the satellite ozone data provide seasonal
variations in the total concentration but these variations could only be substantiated with in-situ measurements of ozone through ozonesondes launched on balloons rising to an altitude of
40-kilometers.

GPS based Ozone Ballon Sounding

The Balloon soundings are conducted with GPS-Radiosondes and a receiver unit along with GPS and UHF antennas. The ozone sensor is an electrochemical cell. Two bright platinum
electrodes are housed in anode and cathode chambers. As soon as air containing ozone flows into the cathode solution a chemical reaction starts. If switch is closed the current can be
measured. Ozonesonde is connected to the radiosonde, which measures pressure, temperature humidity, wind-speed and wind-direction using the satellite GPS technique.

Objectives

To study ozone transport, formation and its variation (seasonal and latitudinal variations) near and above the ground

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To study temperatures and dynamic behaviours of the troposphere and stratosphere

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In situ information for comparison with other in-situ measurements in the region as well as with remote measurements of Ozone with satellites

Ozonosonde Observation

GPS based balloon-sounding carrying ozonesonde and radiosonde was conducted at SUPARCO's Karachi Ionospheric Station (24.87 °N 67.03 °E). The flight was
carried out on 16 Jan 2004 up to an altitude of about 36 kms to measure the vertical profile of the O3 trends. The maximum O3 observed 12.65 mPa at 27 kms.